Question 1: The breathing mechanism involves the inhalation and exhalation of air, which is essential for gas exchange in the lungs. It relies on the movement of the diaphragm and intercostal muscles to change lung volume and pressure.

Answer: The breathing mechanism involves inhalation and exhalation, where the diaphragm and intercostal muscles change lung volume to enable air movement for gas exchange.

Question 1: Define 'tidal volume' in the context of lung capacity.

Answer: Tidal volume is the amount of air inhaled or exhaled during normal breathing.

Question 2: Explain how the diaphragm's movement affects lung volume during breathing.

Answer: When the diaphragm contracts, it moves downward, increasing lung volume and causing air to flow in. When it relaxes, it moves upward, decreasing lung volume and expelling air.

Question 1: A person inhales 500 mL of air during normal breathing and exhales 600 mL. Calculate their inspiratory reserve volume if their tidal volume is 500 mL and their residual volume is 1200 mL.

Answer: Inspiratory Reserve Volume = (Tidal Volume + Inspiratory Reserve Volume) - Tidal Volume = 500 mL (assumed) + (unknown). To find IRV, use data: IRV = (Total lung capacity) - (Tidal volume + Residual volume). Assuming total lung capacity is 4200 mL, IRV = 4200 - (500 + 1200) = 2500 mL.

Question 2: If a person's vital capacity is 3500 mL and their residual volume is 1200 mL, what is their total lung capacity?

Answer: Total Lung Capacity = Vital Capacity + Residual Volume = 3500 mL + 1200 mL = 4700 mL.

Question 1: Describe a simple experiment to measure someone's tidal volume without using specialized equipment. Include the variables involved and safety precautions.

Answer: Students can measure tidal volume by having the person breathe normally into a large, graduated container or water displacement setup. Variables include the volume of air inhaled/exhaled. Safety precautions involve ensuring the person is comfortable, avoiding overexertion, and conducting the experiment in a well-ventilated area.

Question 1: A group of students recorded their tidal volumes as follows: 480 mL, 500 mL, 520 mL, 490 mL, and 510 mL. Calculate the average tidal volume and suggest what this indicates about their breathing pattern.

Answer: Average tidal volume = (480 + 500 + 520 + 490 + 510) / 5 = 500 mL. This indicates a normal and consistent breathing pattern among the students.

Question 1: Explain how the diaphragm and intercostal muscles work together during inhalation and exhalation. (6 marks)

Answer: During inhalation, the diaphragm contracts and moves downward, increasing thoracic volume. The external intercostal muscles contract, raising the ribs and further expanding the chest cavity. This creates a pressure difference, causing air to flow into the lungs. During exhalation, the diaphragm relaxes and moves upward, decreasing thoracic volume, and the external intercostal muscles relax, lowering the ribs. This reduces lung volume and pressure, forcing air out.

Question 1: Describe how understanding the breathing mechanism is important in designing ventilators for patients with respiratory issues.

Answer: Understanding the breathing mechanism helps engineers design ventilators that can simulate natural breathing patterns, control airflow and pressure accurately, and ensure patient safety and comfort during respiratory support.